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Preferred Sample Type

Alkaline Phosphatase (ALP) Isoenzymes (APISO)

Suitable Specimen Types

  • Serum
1.0 mL blood

Specimen Transport

First class post to referral laboratory.

Sample Processing in Laboratory

Centrifuge and separate serum. Perform total ALP analysis before sending to referral laboratory.

Sample Preparation

Centrifuge sample and separate serum. Store separated serum at 4ºC prior to sending to referral laboratory.

Turnaround Time

2 weeks from date received by referral laboratory

Sample Stability

4ºC

Alkaline Phosphatase (ALP) Isoenzymes (APISO)

General Information

Alkaline Phosphatase (ALP) in human serum originates from several sources including bone; liver; intestine and placenta. Because of the wide distribution, limited information can be obtained from a total ALP activity assay. The tissue source of elevated ALP in serum, however, can be determined by identifying the individual isoenzyme present in excess.

The individual ALP isoenzymes normally can be separated by electrophoresis according to charge differences. The separated ALP isoenzymes are visualised using a specific chromogenic substrate.

Patient Preparation

None

Notes

Test not required if total serum ALP is in the normal range.

PLEASE NOTE from 01/08/2012, ALP isoenzyme analysis is no longer performed in-house, specimens to be sent to referral laboratory.  All requests will be vetted by the Duty Biochemist.

Reference Range

Reported as a comment:

ALP1

Predominantly liver isoenzyme present.

ALP2

Predominantly bone isoenzyme present.

ALP3

Both liver and bone isoenzymes are present in approximately equal concentrations.

ALP4

Biliary isoenzyme also present.

ALP5

Intestinal isoenzyme also present: this may indicate intestinal disease but also may occur in the absence of pathology in some individuals of blood group O and B after eating.

ALP

Alkaline phosphatase isoenzyme analysis is not indicated when the total alkaline phosphatase is not markedly raised.

Specifications

  • EQA Scheme?: No
  • EQA Status:

    No EQA Scheme available